Apple has released a new Developer Tools package, with improved Java support and other improvements. You can download it for free if your a registered Apple Developer (there's a free online-only developer level available). You can download the whole thing (nearly 200mb), or just the bits and pieces you're interested in.
You need to start at Apple's Developer Connection Member Site, login (register if you aren't already), and the hit the Download link to see the new Dev Tools packages.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20010614014329317